Paper |
Title |
Page |
MOPC063 |
Characterisation of Electron Bunches from ALICE (ERLP) DC Photoinjector Gun at Two Different Laser Pulse Lengths
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211 |
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- Y. M. Saveliev, S. P. Jamison, L. B. Jones, B. D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
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In high-voltage DC photoinjector guns, the laser pulse duration affects the electron bunch characteristics and therefore is an important subject for experimental investigation and in the optimisation of the operation of the gun. Initial experimental study of this effect has been conducted using the Energy Recovery Linac Prototype (ERLP) photoinjector. During the commissioning of its DC photoinjector gun, the electron bunch parameters were measured at two laser pulse durations, ~7ps and ~28ps FWHM. The shorter laser pulse is the intrinsic output of the laser, while the longer pulse was produced with the use of a pulse stacker. The electron bunch parameters that were measured included transverse emittance, correlated and uncorrelated energy spread and bunch length. The experimental results and their comparison with computer simulations are presented and discussed.
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TUPC042 |
Limitations of Electro-optic Longitudinal Electron Bunch Length Measurements
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1149 |
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- S. P. Jamison
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
- G. Berden
FOM Rijnhuizen, Nieuwegein
- W. A. Gillespie, P. J. Phillips
University of Dundee, Nethergate, Dundee, Scotland
- A. MacLeod
UAD, Dundee
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Electro-optic (EO) techniques are becoming increasingly important in ultrafast electron bunch longitudinal diagnostics and have been implemented at various accelerator labs. A crucial aspect of any implementation is a robust assessment of its resolution capabilities. However the assessments of the temporal limitations often differ between groups and the assumptions employed in deriving these limitations are frequently not addressed. With EO measurements of intense CTR pulses and ultrafast Coulomb fields, it may also be necessary to reconsider the validity of the usual interpretation of the EO effect as a phase retardation proportional to the Coulomb field. From a generic analysis of various sources of the temporal limitations we present a summary of the capability of various EO techniques which can be applied to specific implementations with differing laser and bunch parameters. As well as specifying the quantitative limitations and their scaling with experimental parameters, the qualitative effects of distortion in the measured profile are also summarised. Additional limitations, which arise from a breakdown of the phase-retardation interpretation of the EO effect, are discussed.
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TUPC081 |
Single-shot Longitudinal Bunch Profile Measurements at FLASH Using Electro-optic Detection Techniques
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1242 |
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- P. J. Phillips, W. A. Gillespie
University of Dundee, Nethergate, Dundee, Scotland
- V. R. Arsov, H. Schlarb, B. Schmidt, P. Schmüser
DESY, Hamburg
- G. Berden, A. F.G. van der Meer
FOM Rijnhuizen, Nieuwegein
- S. P. Jamison
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
- A. MacLeod
UAD, Dundee
- B. Steffen
PSI, Villigen
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At the superconducting linac of FLASH at DESY, we have installed an electro-optic experiment for single-shot, non destructive measurements of the longitudinal electric charge distribution of individual electron bunches. The profile of the electron bunch field is electro-optically encoded onto a streched Ti:Sa laser pulse. In the decoding step, the profile is retrieved from a spectral measurement of the encoded pulse or from a cross-correlation of the encoded pulse with a 35 fs laser pulse , obtained from the same laser. At FLASH, sub-100 fs electron bunches have been measured during FEL operation with a resolution of better than 50 fs. The electro-optic measurements have been validated with a tranverse deflecting cavity measurements.
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THPP004 |
EMMA - the World's First Non-scaling FFAG
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3380 |
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- T. R. Edgecock
STFC/RAL, Chilton, Didcot, Oxon
- C. D. Beard, J. A. Clarke, C. Hill, S. P. Jamison, A. Kalinin, K. B. Marinov, N. Marks, P. A. McIntosh, B. D. Muratori, H. L. Owen, Y. M. Saveliev, B. J.A. Shepherd, R. J. Smith, S. L. Smith, S. I. Tzenov, E. Wooldridge
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
- J. S. Berg, D. Trbojevic
BNL, Upton, Long Island, New York
- N. Bliss, C. J. White
STFC/DL, Daresbury, Warrington, Cheshire
- M. K. Craddock
UBC & TRIUMF, Vancouver, British Columbia
- J. L. Crisp, C. Johnstone
Fermilab, Batavia, Illinois
- Y. Giboudot
Brunel University, Middlesex
- E. Keil
CERN, Geneva
- D. J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
- S. R. Koscielniak
TRIUMF, Vancouver
- F. Meot
CEA, Gif-sur-Yvette
- T. Yokoi
OXFORDphysics, Oxford, Oxon
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EMMA - the Electron Model of Many Applications - is to be built at the STFC Daresbury Laboratory in the UK and will be the first non-scaling FFAG ever constructed. EMMA will be used to demonstrate the principle of this type of accelerator and study their features in detail. The design of the machine and its hardware components are now far advanced and construction is due for completion in summer 2009.
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